257 research outputs found

    Cold atoms near superconductors: Atomic spin coherence beyond the Johnson noise limit

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    We report on the measurement of atomic spin coherence near the surface of a superconducting niobium wire. As compared to normal conducting metal surfaces, the atomic spin coherence is maintained for time periods beyond the Johnson noise limit. The result provides experimental evidence that magnetic near field noise near the superconductor is strongly suppressed. Such long atomic spin coherence times near superconductors open the way towards the development of coherently coupled cold atom / solid state hybrid quantum systems with potential applications in quantum information processing and precision force sensing.Comment: Major revisions of the text for submission to New Journal of Physics 8 pages, 4 figure

    Формирование и совершенствование оплаты труда на предприятии ООО «Томскнефтехим»

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    Объект исследования - предприятие ООО «Томскнефтехим». Предметом исследования является формирование оплаты труда на данном предприятии. Цель работы – исследование вопросов формирования и совершенствования оплаты труда на предприятии. В процессе исследования применялись научные и специальные методы экономических исследований, а именно диалектический метод, системный и процессный подходы, анализ литературных данных, обобщения, описания, расчетно – аналитический подход и сравнительно – сопоставительный методы. В качестве рекомендации предприятию в отношении экономических методов организации работы специалистов и руководителей и ее эффективности можно предложить ввести систему KPI (ключевых показателей эффективности) оценку способностей и качества работы персонала. Оценка результатов выступает основой для выплаты регулярных премий, то есть у сотрудников появляются возможности зарабатывать больше, а также оценка квалификации и потенциала работника может стать основой для принятия решений по его обучению, карьерному перемещению и эффективной работе на предприятии.The object of study - the enterprise of OOO "Tomskneftekhim". The subject of research is the formation of wage in the enterprise. The aim of this work is the study of questions of formation and improvement of labor payment at the enterprise. In the process of research used scientific and special methods of economic researches, namely the dialectical method, system and process approaches, the literary data analysis, generalization, description, analytical approach and comparative methods. As a recommendation to the enterprise in respect of economic methods of organization of work of specialists and managers and its effectiveness can introduce the KPI system (key performance indicators) the ability and quality of staff. Evaluation of results is the basis for the payment of regular premiums, then the employees have opportunities to earn more, as well as the qualification and potential of the employee can be the basis for decision-making in his training, career displacement and effective work at the enterprise

    Scattering and absorption of ultracold atoms by nanotubes

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    We investigate theoretically how cold atoms, including Bose-Einstein condensates, are scattered from, or absorbed by nanotubes with a view to analysing recent experiments. In particular we consider the role of potential strength, quantum reflection, atomic interactions and tube vibrations on atom loss rates. Lifshitz theory calculations deliver a significantly stronger scattering potential than that found in experiment and we discuss possible reasons for this. We find that the scattering potential for dielectric tubes can be calculated to a good approximation using a modified pairwise summation approach, which is efficient and easily extendable to arbitrary geometries. Quantum reflection of atoms from a nanotube may become a significant factor at low temperatures, especially for non-metallic tubes. Interatomic interactions are shown to increase the rate at which atoms are lost to the nanotube and lead to non-trivial dynamics. Thermal nanotube vibrations do not significantly increase loss rates or reduce condensate fractions, but lower frequency oscillations can dramatically heat the cloud.Comment: 7 pages, 4 figure

    Trapping of ultra-cold atoms with the magnetic field of vortices in a thin film superconducting micro-structure

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    We store and control ultra-cold atoms in a new type of trap using magnetic fields of vortices in a high temperature superconducting micro-structure. This is the first time ultra-cold atoms have been trapped in the field of magnetic flux quanta. We generate the attractive trapping potential for the atoms by combining the magnetic field of a superconductor in the remanent state with external homogeneous magnetic fields. We show the control of crucial atom trap characteristics such as an efficient intrinsic loading mechanism, spatial positioning of the trapped atoms and the vortex density in the superconductor. The measured trap characteristics are in good agreement with our numerical simulations.Comment: 4pages, comments are welcom

    Trapped electron coupled to superconducting devices

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    We propose to couple a trapped single electron to superconducting structures located at a variable distance from the electron. The electron is captured in a cryogenic Penning trap using electric fields and a static magnetic field in the Tesla range. Measurements on the electron will allow investigating the properties of the superconductor such as vortex structure, damping and decoherence. We propose to couple a superconducting microwave resonator to the electron in order to realize a circuit QED-like experiment, as well as to couple superconducting Josephson junctions or superconducting quantum interferometers (SQUIDs) to the electron. The electron may also be coupled to a vortex which is situated in a double well potential, realized by nearby pinning centers in the superconductor, acting as a quantum mechanical two level system that can be controlled by a transport current tilting the double well potential. When the vortex is trapped in the interferometer arms of a SQUID, this would allow its detection both by the SQUID and by the electron.Comment: 13 pages, 5 figure

    An investigation of cognitive 'branching' processes in major depression

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    <p>Abstract</p> <p>Background</p> <p>Patients with depression demonstrate cognitive impairment on a wide range of cognitive tasks, particularly putative tasks of frontal lobe function. Recent models of frontal lobe function have argued that the frontal pole region is involved in cognitive branching, a process requiring holding in mind one goal while performing sub-goal processes. Evidence for this model comes from functional neuroimaging and frontal-pole lesion patients. We have utilised these new concepts to investigate the possibility that patients with depression are impaired at cognitive 'branching'.</p> <p>Methods</p> <p>11 non-medicated patients with major depression were compared to 11 matched controls in a behavioural study on a task of cognitive 'branching'. In the version employed here, we recorded participant's performance as they learnt to perform the task. This involved participants completing a control condition, followed by a working memory condition, a dual-task condition and finally the branching condition, which integrates processes in the working memory and dual-task conditions. We also measured participants on a number of other cognitive tasks as well as mood-state before and after the branching experiment.</p> <p>Results</p> <p>Patients took longer to learn the first condition, but performed comparably to controls after six runs of the task. Overall, reaction times decreased with repeated exposure on the task conditions in controls, with this effect attenuated in patients. Importantly, no differences were found between patients and controls on the branching condition. There was, however, a significant change in mood-state with patients increasing in positive affect and decreasing in negative affect after the experiment.</p> <p>Conclusion</p> <p>We found no clear evidence of a fundamental impairment in anterior prefrontal 'branching processes' in patients with depression. Rather our data argue for a contextual learning impairment underlying cognitive dysfunction in this disorder. Our data suggest that MDD patients are able to perform high-level cognitive control tasks comparably to controls provided they are well trained. Future work should replicate these preliminary findings in a larger sample of MDD patients.</p

    Chronic widespread bodily pain is increased among individuals with history of fracture:findings from UK Biobank

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    Acknowledgments This work was supported by grants from the Medical Research Council, British Heart Foundation, Arthritis Research UK, National Osteoporosis Society, International Osteoporosis Foundation, NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, and NIHR Musculoskeletal Biomedical Research Unit, University of Oxford. This research has been conducted using the UK Biobank Resource. Compliance with ethical standards.Peer reviewedPublisher PD
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